Congress electing the president has only really happened twice in history — 1800 and 1824. In the last election, the National Constitution Center predicted that such an event would result in a Mitt Romney presidency with Joseph R. Biden Jr. as vice president.

Here’s how that could happen

In the wake of the confusing 1800 election, Congress ratified the 12th Amendment , which laid out what would happen in the event of a tie.

It reads, “The House of Representatives shall choose immediately, by ballot, the President” and “the Senate shall choose the vice president.”

All representatives within a given state vote as a bloc with each state having one vote, determined by the majority of votes in the bloc.

If the House fails to decide, the vice president acts as president.

The amendment reads, “If the House of Representatives shall not choose a president whenever the right of choice shall devolve upon them, before the fourth day of March next following, then the vice president shall act as president, as in case of the death or other constitutional disability of the president.”

Remember: This was before the 20th Amendment moved the start of a new session of Congress to January.

Spoiler alert

In "Veep's" fifth season, Selina Meyer (Julia Louis-Dreyfus) failed to receive the 270 electoral votes needed to win. She helped get Jonah Ryan (Timothy Simons) a New Hampshire congressional seat to give her an extra vote in the House. But, three states abstained in the House vote which meant that neither Meyer nor her opponent ended up with a majority.

So with the presidency still vacant, the Senate vote on vice president should determine who will be president. And (stop reading if you haven’t seen the season finale), there’s a tie in the Senate. So, the president of the Senate — the sitting vice president — breaks the tie for vice president.

In this case — stay with me — Meyer’s sitting vice president (Andrew Doyle played by Phil Reeves) votes against her vice president on the new re-election ticket (Tom James played by Hugh Laurie) because he was promised secretary of State by the other vice presidential candidate (Laura Montez played by Andrea Savage).

Even stranger, a real-life split White House in 2012 could have happened if the Electoral College vote ended in a tie. After the 2012 election, Republicans ran the House and would likely have elected Romney as president. But, Democrats ran the Senate and would likely have selected Biden as vice president.

History lesson

In 1800, Thomas Jefferson was the Democratic-Republican candidate and Aaron Burr was his vice presidential candidate. Jefferson and Burr each received 73 electoral votes for president so the decision fell to the lame duck Congress at the time.

The House elected Jefferson over his running mate, Burr. The 12th Amendment then decided electors would vote separately for president and vice president.

In 1824, a split among four candidates caused no one to get the majority. Andrew Jackson won the popular vote with about 41 percent but third place, Henry Clay, agreed to support John Quincy Adams, second place, in exchange for Secretary of State. So with Clay’s sway, the House chose Adams as president.